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Eliminating Obliquity Error from the Estimation of Ionospheric Delay in a Satellite-Based Augmentation SystemCurrent satellite-based augmentation systems estimate ionospheric delay using algorithms that assume the electron density of the ionosphere is non-negligible only in a thin shell located near the peak of the actual profile. In its initial operating capability, for example, the Wide Area Augmentation System incorporated the thin shell model into an estimation algorithm that calculates vertical delay using a planar fit. Under disturbed conditions or at low latitude where ionospheric structure is complex, however, the thin shell approximation can serve as a significant source of estimation error. A recent upgrade of the system replaced the planar fit algorithm with an algorithm based upon kriging. The upgrade owes its success, in part, to the ability of kriging to mitigate the error due to this approximation. Previously, alternative delay estimation algorithms have been proposed that eliminate the need for invoking the thin shell model altogether. Prior analyses have compared the accuracy achieved by these methods to the accuracy achieved by the planar fit algorithm. This paper extends these analyses to include a comparison with the accuracy achieved by kriging. It concludes by examining how a satellite-based augmentation system might be implemented without recourse to the thin shell approximation.
Document ID
20150007499
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Sparks, Lawrence
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
May 6, 2015
Publication Date
April 22, 2013
Subject Category
Communications And Radar
Meeting Information
Meeting: Pacific PNT
Location: Honolulu, HI
Country: United States
Start Date: April 22, 2013
End Date: April 25, 2013
Sponsors: Institute of Navigation
Distribution Limits
Public
Copyright
Other
Keywords
delay estimation
global positioning system (GPS)
ionosphere
thin shell model
Wide Area Augmentation System (WAAS)

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